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Beam and boom

 Réne Kleiss, Vice President, Harbour Cranes at Cargotec, the Netherlands points out that future developments are likely to include an increased level of integrated automation in the ship-to-shore operation and more data exchange between STS cranes and Terminal Operating Systems (TOS). For example, an automated twist lock system has been increasingly discussed as a possible development. It would eliminate the need for dockworkers on the ground therefore increasing safety in the terminal.

His views about automation are shared with Thomas Kittel, Product Manager at Prysmian, Germany, who believes that more intelligent systems will become more and more popular. “This means sensitive components combined with active capability will lead to more reliable operations. In other words: whenever extreme stress situation occurs (on the main power supply cable in particular), that might be caused by human or technical failing, the diagnostic system raises the red flag indicating immediate action is required to avoid a breakdown,” explains Kittel. “Even for trouble-free operations the diagnostic system indicates by raising a green flag that everything is in good condition. The “flags” are represented by a traffic light and the information can be used even further as an active input for the crane control system. All in all this system is full of potential and opens the door to really advanced operational safety and supports the more and more upcoming fully automated terminal operation.” Other developments expected in the next ten years are likely to include advancements in energy saving technology. Due to ever-stringent government regulations, it is likely that more electrically-powered and less hydraulic- and diesel-powered machinery will be used at ports to help reduce emissions (see article on Straddle Carriers).

 

Environmental issues are a hot topic at Konecranes, Finland, typically with yard cranes discussions involving the use of fuel and renewable stored energy, with customers asking for detailed information on the environmental policy of the manufacturing process to help in their purchasing decisions. Furthermore, the container yard and the equipment need to match the higher volumes coming from the quay cranes. Therefore Konecranes has been focusing on the load control technology for reducing the cycle time and improving the overall productivity. For example, with high peak performance capability (due to advanced load control technology) it is possible to allocate less yard cranes to serve STS cranes, which in turn saves costs, reduces emissions and can increase the level of truck service. Besides the further development of STS components, future technological advancements could include the introduction of the fully-automated STS crane. Incorporating automation into cargo handling not only offers advantages in efficiency and safety with a 24/7/365 unmanned operation, but environmental benefits could be achieved through the use of precision handling. More and more terminal operators are considering options to outsource their operations to free up capital and to employ a more flexible cost structure. “The ultimate outsourcing option – “pay per move” – would reduce operational costs even more if applied to the operations of STS cranes. Cargotec already offers this service on its yard cranes and counterbalance equipment,” said Kleiss.

 

Global downturn

The global economic downturn has brought misery for many cargo handling equipment manufacturers but many agree that things are picking up. According to Konecranes, the first sign of the recovery will be the increased activity of crane tenders with the start of a flux of STS cranes orders followed by other container handling equipment. But for now, the company has received an increased interest in second-hand cranes, and the requirement for the refurbishment of existing cranes. It also received more interest in their Crane Monitoring System (CMS) – a remote maintenance monitoring system.  Another observation made by Konecranes is that there is less interest in mega and tandem lift units and more enquiries in favour of smaller models. This interest might be generated by the numerous postponement of the development of new large terminals at present or the productivity improvement expected with tandems has not been as impressive when compared to a single hoist crane. Konecranes also points out that the size of potential orders has decreased, with most relating to one or two cranes rather than the multiple orders of the recent boom years.

 

High tech spec

Another issue that often comes up is the construction of the main beam/boom and opinions continue to vary. Numerous crane manufacturers are ‘going’ for the double box girder, while Liebherr Container Cranes (LCC) from Killarney, Ireland, successfully applies the lattice type rectangular cross section construction using high tensile box/square sections for the crane main beam and boom.  According to LLC the lattice design is the optimum solution providing rigidity and stiffness to the beam and boom. Other advantages include a rigid structure reducing structural sway and improved crane productivity, reduced wind forces generated on the crane structure and the crane wheel loadings on the quay rails are significantly reduced due to less weight. LCC is also using high tensile steel (S355) [formerly ST52.3] for all main structural components. This high tensile steel – although more expensive – also allows a lighter overall construction of the cranes and a reduced wind area. The joint design details used on their container cranes are customised to suit the particular joint configurations required at any one location and are validated using Finite Element Analysis software. This design philosophy ensures that the load is distributed thr
ough the member joints and structure members in an efficient manner resulting in low stress concentrations. As the notch/stress raisers are engineered to low levels, this allows the joint and structure members to withstand greater loads and endure additional load cycles as the joint’s fatigue tolerance is also increased. Demand for LCC STS container cranes in recent years has mainly been for super-post-panamax and mega-max specifications, with an outreach of 55m to 65m. Most recently, the company delivered the first Liebherr 80 tonnes tandem lift cranes to the Port of Khorfakkan, UAE. However, the company emphasises that it is market-driven and does not try to encourage a terminal to order cranes which are larger than its needs. While this article might bring various [commercial] opinions to the table there is a definitive interest from crane manufacturers to provide a first class product equipped with the latest technical developments for their client. Although this might be a challenge the technology is already available in other industries – it just has to be adjusted and applied to the industry! Our Container Crane & Components Supplement published with our May 2010 issue of World Port Development will highlight some of these technologies.

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